Inner Forestay Addition

I’ve been keeping this one a bit of a secret, there is just so much that goes into it that I wanted to have everything lined up before committing!  We are adding an inner forestay to the boat and I am pretty excited about it.

inner stay.jpg

The above is my rough sketch of the new sail plan using the sail plan from BlueWaterBoats.org.  Please do not use this to rig your boat, its just a rough sketch that I am still playing with.

As you can see I have decided to rig a true inner stay, not a solent.  This was not an easy or quick decision as there are pros and cons of each design.  From my point of view the deciding factor was the chain locker / v-berth bulkhead was in the perfect location to bring the forestay down to.  As we are going to use this primarily for a storm jib in heavy weather, I also really like bringing the idea of bringing the center of effort inwards.


Anecdotal story here (this is from memory and my details could be off): My father and I were on their Bristol 41.1c S/V Skylark (on which they rigged a solent stay) discussing the whole inner stay idea and he told me that he once met Walter Shulz who founded Shannon Yachts.  They were talking and for whatever reason the inner stay thing came up and Shulz was apparently pretty adamant that the stay should be placed as far forward as practical, the advantage being able to better claw off a lee shore if one were in such a situation.  Whether or not I have missed a detail here or there, the general sentiment has stuck with me.  And yet here I am, not taking either of their advice.  And, in no particular order, this is why: 1) other A37 owners have successfully rigged an inner stay in the exact location we are going to.  2) the A37 is a classic design and I personally believe that moving the center of effort inwards on this type of design results in greater stability. 3) our boat was already halfway rigged for an inner stay and the mast tang already installed by the spreaders.


 

So, haunted by Walter Shulz as I am, I have none the less decided to proceed with the design above.

The planning has taken ages, and like everything else is much more complicated that I had originally intended.  But here’s the basic premise: We have a beautiful external wrap around tang already riveted to the mast by the spreaders.  Attached to this will be a wire stay led down to the deck which will attach to a double folding pad eye (19,800lbs breaking strength).  The pad eye will be through bolted to a four inch 6061 aluminum C channel beam.  This beam will be through bolted both fore and aft to two bulkheads exactly four inches apart. Both of these bulkheads are structural and are well fiber-glassed to the hull.  The loads on the mast will be counteracted by single line running back-stays.  The back-stay will attach at the spreaders using a T-Ball fitting on each side on which a Dyneema line will be spliced.  The line will lead aft to a turning block attached to a folding pad eye on both port and starboard sides and led to the windward winch.   When not in use we can easily tie off the dyneema lines and unclip or leave the removable turning blocks.   Tension is created entirely with the winch, no block and tackle flying around or getting in the way when not in use.

So! Thats a bunch of talk!  Lets take a look shall we?

Here is our beautiful pad eye:

BTW: the reason I like the folding pad eye instead of a chainplate is two fold – one, we are not going to use this thing 90% of the time and we don’t want to be stubbing our toes on an unused chainplate sticking straight out of the deck!  Two: this is a fantastic place to clip on when doing fore-deck work and could also be used to run jack lines.

Here is our beautiful c-channel beam:

This is made of 6061 aluminum which is extremely corrosion resistant but still light weight.   Oh, and its very very strong 🙂

And finally here is our beautiful new bulkhead:

2015-12-20 13.53.43.jpg

This bad boy is 3/4 inch okoume wood, known for its excellent boat-building qualities (one of which being strength!).  I also think its quite pretty and cant wait to oil it after its fiber-glassed in place.

It turned out to be quite the task to fabricate this bulkhead.  First I created a mock up using cardboard:

I was really worried that once I cut the wood in the correct dimensions it would not fit into the chain locker!  This was a very real concern and took a lot of energy to resolve but I eventually got the perfect dimensions to fit through the chain locker door, turn around in the locker, and be pulled aft to its resting place where it will be fiber-glassed in.  Here is the final mock up and transfer onto the wood:

 

And while I sadly do not have a truck, I totally pretend like I do:

 

Here is the “dry fit” of the bulkhead:

 

And here is the “dry fit” of the c-channel in between the two bulkheads:

2015-12-20 14.27.11.jpg

So there you have the progress up to this point.  I have started grinding down the fiberglass in the chain locker so that I can fiberglass the new bulkhead in place but its rough work.

By the way, for those of you who’ve read all this way, I have one confession to make:  we were going to install this second bulkhead anyhow and it just so happened to converge with the inner forestay idea nicely.

The REAL reason for the second bulkhead is to extend the V-berth so I can lie down straight at night!! haha.  More on that to come soon 😉

 

 

 


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